
\subsection{Introduction}
Diskmodel is a library implementing mechanical and layout models of
modern magnetic disk drives.  Diskmodel models two major aspects of disk
operation.  The layout module models logical-to-physical mapping of
blocks, defect management and also computes angular offsets of blocks.
The mechanical model handles seek times, rotational latency and
various other aspects of disk mechanics.

The implementations of these modules in the current version of
Diskmodel are derived from DiskSim 2.0 \cite{Ganger99}.  Disksim 3.0
uses Diskmodel natively. Diskmodel has also been used in a device
driver implementation of a shortest positioning time first disk
request scheduler.
